Utility knife with movable and rotatable blade



July 7, 1970 R. AIBENNETT 3,518,758

UTILITY KNIFE WITH MOVABLE AND ROTATABLE BLADE Filed Oct. 24, 1967 2 Sheets-Sheet 1 FIG.!

INVENTOR ROBERT A. BENNETT ATTORNEYS July 7, 1970 R. A. BENNETT 3,518,753

UTILITY KNIFE WITH MOVABLE AND ROTATABLE BLADE Filed Oct. 24, 1967 2 Sheets-Sheet 2 J /IIIIIIIIIIIII E YIIII'IIIIIIIIA I II I III II INVENTO ROBERT A. B ETT ATTORNEYS United States Patent 3,518,758 UTILITY KNIFE WITH MOVABLE AND ROTATABLE BLADE Robert A. Bennett, Lot 6, Falmouth Drive,

Huntington, Conn. 06484 Filed Oct. 24, 1967, Ser. No. 677,530 Int. Cl. B26b 1/00 U.S. Cl. 30-154 8 Claims ABSTRACT OF THE DISCLOSURE A utility knife having a blade which is movable from a position entirely within the knife handle to one with an exposed cutting edge in a series of steps and in which a locking arrangement is provided which permits the blade to be turned to a scraping position and also to expose another portion of the blade for cutting without disassembling the knife handle.

Utility knives are of great use to home owners and others who have need for a general purpose knife which has a variable length cutting blade. Such knives also find added usefulness if they can be used for other purposes such as scraping windows.

In the past, knives have been sold in which a razor blade is located within a handle and some arrangement is provided to move the blade in fixed increments or continuously along the length of the handle to extend more or less of the blade length for cutting purposes. In some of these prior art knives it is possible to use the same blade for a scraper and also to turn the blade around, so that another portion of it can be used for cutting purposes, thereby insuring that the entire cutting edge of a single razor blade is used rather than just half of the edge. While this has been possible with certain prior art knives, it has generally been necessary to disassemble the knife both to adjust it for use as a scraper and also to reverse the blade in the knife handle, so that another portion thereof can be used for cutting purposes.

The present invention provides a utility knife of simplified construction in which a blade can be easily extended or retracted in incremental steps. In addition, the knife of the present invention has the capability of readily turning the knife blade by a fixed angle, for example, 90, from its cutting position to a scraping position without disassembling the knife and also to reverse the blade so that another portion of it can be used for cutting purposes.

In accordance with the present invention, a novel utility knife is provided having a locking member which rides in a detent track. The locking member is biased outwardly by a spring to normally be in a locking position with the detent and the blade is moved longitudinally by depressing the spring and sliding the locking member along the detent track. The locking arrangement is made so that the locking member can be depressed to clear the detent so that the blade can be turned to a desired position.

Accordingly, it is an object of the present invention to provide a utility knife in which the blade can be moved in incremental steps to expose a greater or lesser amount of cutting edge and also turned without disassembling the knife.

A further object is to provide a utility knife with a novel locking arrangement.

An additional object is to provide a utility knife in which the locking member is spring-biased normally into a locking position.

A further object is to provide a utility knife which can be used as a scraper and the blade turned to expose a new cutting edge without disassembling the knife.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings, in which:

FIG. 1 is a perspective view of the knife showing the blade extended in a scraping position;

FIG. 2 is an elevational view of a knife blade;

FIG. 3 is an elevational view showing the inside of one half of the handle;

FIG. 4 is a side elevational view showing the inside of the other half of the handle;

FIG. 5 is a top view of the assembled knife of FIG. 1 taken in section approximately through the center;

FIG. 6 is an enlarged top view showing a fragment of the front end of the knife in cross-section with the blade extended in scraping position;

FIG. 7 is a fragmentary view of the front portion of the knife taken in section showing the blade in an extended cutting position;

FIG. 8 is an end view of the locking bolt; and

FIG. 9 is an exploded perspective view of the locking member formed by the locking bolt, spring washer and knob.

Referring to FIGS. l5, the knife 10 of the present invention comprises an elongated handle having two sections 12 and 14. The handle sections are preferably cast of metal or molded of plastic. For greater strength, it has been found that metal is more desirable. As shown best in FIGS. 3 and 5, handle section 12 has a depressed interior compartment 15 with a floor of generally rectangular shape except for the curved rear end of the handle. Walls 16 taper downwardly from the inner face of the knife section 12 to the floor of compartment 15.

A threaded, cylindrical stud 18 projects upwardly from the floor of compartment 15 near the center of the handle section and an unthreaded stud 19 projects upwardly from the compartment floor near the curved end of the handle. A post 20 which can be round or polygonal, also projects upwardly from the compartment floor near its center. As shown most clearly in FIG. 3, a number of ribs 21 extend inwardly from the edge of the wall 16 at one side along the long portion of the handle section into the compartment area 15. The use of these ribs 21 for holding blades is described in detail below.

A keyhole shaped slot 23 with an elongated portion 24 and a circular end portion 25 near the front end of the knife is formed in the front of the handle section 12. As seen in FIGS. 57, the keyhole slot 23 extends only partially through the handle section 12 and the hole 25 is spaced back from the end of the knife. A pair of raised guides 29 are also formed on the inner face of the handle section 12 adjacent the compartment 15. The guides 29 extend toward the front end of the knife for a distance sufficient to permit the blade to clear them when the blade is fully extended.

Referring to FIG. 4, the other handle section 14 has an overall shape complementary to the section 12 and has a complementary depressed compartment 30 formed therein tapering down from walls 31. The compartment 30 can be eliminated, if desired. Cap members 33, 34 and 35 extend upwardly from the floor of compartment 30 to fit over the corresponding studs 18 and 19 and the post 20 of the handle section 12.

As shown in FIGS. 4-7, the front portion of handle section 14 has a smooth end area 37 in which is formed a depressed detent track 39 having an elongated slot 40 which lies outwardly of a plurality of semi-circular detents 42. It should be noted that the members of a pair of semi-circular detents 42 oppose each other along the length of the track 39 and therein is an opposing semicircular detent at each end of the track. Slot 40 extends completely through the wall of the handle section 14 into a generally triangular shaped depressed area 47 on the outer face of handle section 14 which is provided to accommodate the thumb of a user of the knife (see FIG. 1).

As shown in FIGS. 8 and 9, a locking member 50 is provided which is formed by a bolt 52 having a threaded end 54 and a head 56 of generally square shape at the other end. A set of locking tabs 58 are located on the bolt at the inner end of the head 56. The locking tabs 58 are formed in a generally cloverleaf shape here shown as having four tabs spaced 90 apart. Each tab matches and is capable of riding into one of the detents 42 of the handle section 14.

The locking member is completed by a conical spring washer 57, commonly called a Belleville spring, which fits over the unthreaded portion of bolt 52. A knob 59, which may be knurled if desired, has threads thereon which mate with the threads 54. As described below, the knob 59 is staked to the bolt 52 during assembly of the knife.

FIG. 2 shows one type of blade 60 which can be used with the present invention. As shown, the blade 60 is of generally trapezoidal shape and has a cutting edge 62 at the base of the trapezoid. A central aperture 64 is provided which is of the same shape as and slightly larger than the head 56 of the locking member 50. Similarly, three cutouts 66 are located on the upper side of the blade to mate with the ribs 21 in handle section 12 to hold the blade in compartment 15. It should be noted that the locking member head 56 and the blade aperture 64 can be of any complementary, mating shape in which the head is not free to rotate within the aperture. For example, the head and aperture can be triangular.

The knife is assembled in the following manner. First, the bolt 52 of the locking member is inserted into the slot 40 of the detent track 39 of handle section 14 by passing the threaded end 54 of the bolt from the inside of handle section 14 through the slot. The spring washer 57 is then placed over the unthreaded portion of the bolt and the knurled knob 59 is fastened onto threads 54 and staked thereto to prevent it from being removed. As should be apparent, the bolt 52. is held within the handle section 14 since the tabs 58 are larger than the width of slot 40.

After the locking member 50 is assembled, a blade 60 is placed in the front end of the handle section 14 with the head 56 of the locking member 50 passing through the correspondingly shaped aperture 64 of the blade. The two halves 12 and 14 of the handle are then put together by placing the caps 33, 34 and 35 of section 14 over the corresponding studs 18, 19 and post 20 of section 12. The blade 60 is aligned between the two raised guides 29. The two halves are then fastened together by a headed screw 70 which passes through the cap 33 and screws into the internally threaded stud 18. It should be noted that the locking member head 56 extends into the keyhole slot 23 of handle section 12.

As seen best by referring to FIGS. 1, 6 and 7, the operation of the knife is as follows. The tabs 58 of the locking member ride in the detents of the detent 42 track 39 and are of sufficient size to mate therewith. The head 56 is Only slightly smaller than the aperture of the blade to provide a fairly tight fit so that the blade is moved as the locking member is moved. When the knob 59 of the locking member 50 is not depressed by the thumb of the operator, the spring washer 57 applies pressure outwardly between the outer face of handle section 14 and the knob 59. This moves the locking member outwardly thereby locking a pair of opposing tabs 58 in a pair of the detents 42. This prevents the blade from being moved longitudinally (into or out) of the handle.

When it is desired to extend or retract the blade 60 in a cutting position, as shown by the dotted line position of FIG. 1, it is only necessary to depress the knob 59. This moves the tabs 58 of the locking member 50 toward the slot 23 of handle section 12, clearing the tabs 58 from the detents 42. As shown in FIG. 7, the head 56 of the locking member extends further into the slot 23 when the knob 59 is depressed. With the knob 59 depressed and the tabs 58 cleared from the detents the blade 60 can be moved longitudinally out of handle for a desired distance limited by the lengths of the slots 24 and 40 merely by moving the knob. When the desired length of the blade has been extended or retracted, it is necessary only to release the knob 59. This, as shown in FIG. 6, causes the spring washer 57 to push back the locking member 50 causing the tabs 58 to lock in the detents 42. The blade 60 is preferably properly sized so that the blade can be fully retracted into the housing with the locking member to the extreme right. The detent at the extreme right end of track 39 (FIG. 4) permits the locking mem ber to be moved fully to the right while the detent at the extreme left of the track locks the blade fully extended, as shown in FIGS. 6 and 7. In the fully extended cutting position of FIG. 7, only about one half of the blade edge is exposed.

One important advantage of the present invention is that it permits the blade to be extended to a scraping position, such as shown in FIG. 6 or to be completely reversed so that the other half of the blade can be used as a cutting edge without taking the handle apart. As shown 1n FIG. 3, the circular end 25 of the slot 23 is large enough to permit rotation of the square head 56 of the locking member. This is the only place where the head 56 can be rotated since the slot 24 is of a size to permit .a clearance fit of the head for sliding longitudinal movement but not permit its turning therein. When the blade 60 1s fully extended (FIG. 7) at which time the head 56 is in the circular hole 25, depressing knob 59 clears the tabs 58 from the detents and the blade 60 can now be turned by rotating knob 59. Since there are four tabs 58 on the locking member, rotation of the blade 60 is in steps of degrees. When the blade is turned 90 degrees from the dotted line position, shown in FIG. 1, it will assume the scraping position shown in FIGS. 1 and 6. While in the scraping position shown in FIG. 1, the knob 59 also can be depressed to adjust the protrusion of the blade from the end of the handle. The locking member 50 holds the blade in the same manner previously described as when the blade is in the cutting position.

As shown in FIG. 6, the nose of the knife is tapered at portions 72 on both handle sections 12 and 14, so that with the blade in the scraper position and fully extended an angle of about 30 degrees is obtained, as shown. This has been found to be particularly advantageous in scrapmg paint from windows.

To fully utilize the entire blade for cutting, since normally only about one half of the blade is exposed when fully extended, it is only necessary to move the lockmg member 50 fully forward to the position shown in FIGS. 57, depress knob 59 and then rotate the blade 189 degrees. This brings the half of the blade within the knife to an exposed cutting position and places the pre- 'VlOllSlY exposed half of the blade within the handle. Thus, the entire cutting edge of the blade can be used Without having to disassemble the handle, as is common with most knives currently being sold.

To change blades, it is necessary that only the screw 70 be removed, so that the handle sections 12 and 14 can be taken apart. The blade held by the locking member 50 is removed and a new blade is placed over the square head of the locking member. The two halves of the knife are ghen reassembled and the screw 70 inserted and tightene As shown in FIG. 3, a number of extra blades 60 may be held in the compartment 15. These blades fit with their apertures 64 over the post 20 with the ribs 21 fitting into the circular grooves 66 of the blade. Thus, the blades are held in the compartment 15 securely and will not rattle or turn around when the second half 14 of the compartment is placed thereover, as shown in FIG. 5. The cap 35 of handle section 14 holds the blades securely.

:While a preferred embodiment of the invention has been described, it will be understood that it is illustrative only, and the invention is to be limited solely by the appended claims.

What is claimed is:

1. A utility knife comprising a blade formed with a keyed aperture, a handle having two sections defining an interior passage along which said blade moves toward and away from the front of the handle, the front of the handle formed with an opening through which said blade can extend and be rotated, means for holding the two handle pieces together, one of said sections formed with a through elongated slot along a portion thereof, a looking member having a head portion complementary to the keyed aperture of the cutting blade to engage the cutting blade and form an actuating member to move and rotate the blade and an end which extends through said slot exterior to said one section, cooperating means including an extending member on said locking member and a plurality of detents into which said member fits formed adjacent the'slot along a generally straight line for holding said locking member and said blade in one of a number of predetermined positions along the slot, said handle also formed with at least one other detent adjacent the end of said slot at the front of the handle at an angle to the line of the other detents into which said extending member can fit upon rotation of the locking member to hold said blade at at least one other angle than that defined by the first named detents, and means for normally operating said locking member to actuate said extending member to fit into a said detent to prevent movement of the locking member and blade relative to said handle.

2. A utility knife as set forth in claim 1 wherein said detents are formed in said one handle section adjacent said through slot.

3. A utility knife as set forth in claim 1 wherein said operating means comprises a spring washer which urges a said extending member into a detent.

4. A utility knife as in claim 1 wherein said other detent is at an angle of substantially not more than 90 with respect to the line defined by the first named detents, the tab of said locking means when in said other detent holding the blade with its edge at said angle.

5. A utility knife as in claim 1 wherein said other detent is facing in the opposite direction from the first named detents, said locking means rotating the blade by substantially 180 when in said handle opening to engage the extending member in said other detent and hold the blade in position.

6. A utility knife as in claim 1 wherein there are two lines of detents lying opposite each other and facing in generally opposite directions on each side of said elongated slot, and the one other detent is between said two lines of detents and is at an angle different from the detents of the two lines.

7. A utility knife as in claim 6 wherein said extending member of said cooperating means on said locking means has a three sided tab, two of said tabs fitting into respective detents of said two lines or detents and the third tab fitting into said other detent.

8. A utility knife as in claim 7 wherein said extending member has four tabs, any three of which can engage the detents upon rotation of the locking member.

References Cited UNITED STATES PATENTS 1,830,729 11/1931 Wood 203 2,650,422 9/ 1953 Soltow et al. 30-154 2,830,831 4/1958 Bosch 285347 2,869,233 1/1959 Mahoney 30--162 2,870,537 1/1959 Ortner 30-162 3,078,572 2/1963 Everton 30-333 3,063,147 11/1962 Paparelli 30154 LESTER M. SWINGLE, Primary Examiner J. c. PETERS, Assistant Examiner US. Cl. X.R. 

